Earth-boring drill bit with chisel cutter

ABSTRACT

The present invention provides non-planar cutting tooth and a diamond drill bit. The non-planar cutting tooth and the diamond drill bit have great ability of impact resistance and balling resistance. According to the features of drilled formation, cutting teeth are arranged on the drill bit with different mode, which can improve the mechanical speed and footage of the drill bit.

FIELD OF THE INVENTION

The disclosure relates generally to a drill bit. The disclosure relates specifically to a drill bit including a certain optimal polycrystalline diamond compact cutter shape for use in the field of drill bits for petroleum exploration and drilling operations.

BACKGROUND OF THE INVENTION

The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.

At present, diamond drill bits are widely used in petroleum exploration and drilling operations. This kind of bit consists of a bit body part and diamond composite sheet cutting tooth, the bit body part is made of sintered tungsten carbide material or is formed by processing a metal material as a substrate, and the diamond composite sheet cutting tooth is brazed to the front end of the cutting face of the blade of the bit. In the drilling process, diamond composite sheet cuts rock and withstands great impact from the rock at the same time. They are prone to impact damage when drilling into a high gravel content formation or a hard formation, resulting in damage to the cutting faces. On the other hand, when drilling in shale, mudstone and other formations, the debris produced by cutting through diamond composite sheet can easily form a long strip shape debris. Due to the large size of this kind of debris, it will easily attach to the blades and body part of the bit to form balling, such that the cutting work faces of the blades of the bit are wrapped and unable to continue working, eventually leading to decrease of mechanical speed, no drill footage and other issues. The day rate is very high during the process of drilling. The replacement of the drill bit in virtue of the poor impact resistance or as a result of the decreased mechanical speed owning to the balling will bring high economic costs, so it has become a top priority to effectively improve the ability of impact resistance and the balling resistance of the drill bit.

Downhole drilling applications for oil and gas are challenging due to high temperature, high pressure, impact, and abrasion. Both the drill bit and polycrystalline diamond compact (PDC) cutter lifespan and performance are decreased by heat, stresses around individual cutters, and abrasion. It would be advantageous to have a PDC cutter with improved geometry for cooling and cutting evacuation and efficiency.

SUMMARY OF THE INVENTION

Towards these and other objects of the method of the present invention (hereinafter, “the invented method”) that are made obvious to one of ordinary skill in the art in light of the present disclosure, provided herein is a drill bit to advance a borehole, comprising a bit body having a face on which is defined a plurality of blades extending from the face and separated by channels between the blades, each said blade supporting a plurality of first cutters; and at least one of the plurality of blades supporting at least one of chisel cutter, wherein the at least one chisel cutter has a top surface with two joining edges that extend to define an acute angle. In some embodiments, the drill bit might have at least one of the plurality of first cutters comprising polycrystalline diamond compact (“PDC”).

In some embodiments the drill bit might have at least one of the plurality of first cutters defining a depression extending from the top surface and towards a central longitudinal axis of the bit body. Additionally, that embodiment might also include at least one of the plurality of first cutters comprising polycrystalline diamond compact (“PDC”). In some embodiments the at least one of the plurality of first cutters comprises hot isostatic segments. In some embodiments the at least one of the plurality of first cutters comprises hot diamond elements coated with a metal binder. In some embodiments the at least one of the plurality of first cutters comprises diamond elements sintered within a tungsten carbide matrix. In some embodiments the at least one of the plurality of first cutters comprises hot diamond elements coated with a metal binder. In some embodiments the at least one of the chisel cutters comprises hot isostatic segments. In some embodiments the at least one of the chisel cutters comprises hot diamond elements coated with a metal binder. In some embodiments the at least one of the chisel cutters comprises diamond elements sintered within a tungsten carbide matrix. In some embodiments the at least one of the chisel cutters comprises hot diamond elements coated with a metal binder.

In some embodiments the at least one chisel cutter is positioned more distally from a central longitudinal axis of the bit body than at least one of the plurality of first cutters. In some embodiments the at least one chisel cutter being positioned more distally from the central longitudinal axis of the bit body than all of the plurality of first cutters.

In some embodiments the drill bit further comprises an at least one tungsten carbide cutter supported by the at least one blade of the plurality of blades. Additionally, this embodiment might further comprise a plurality of tungsten carbide cutters supported by the at least one blade of the plurality of blades. Additionally, this embodiment might further comprise the at least one chisel cutter as positioned more distally from a central longitudinal axis of the bit body than at least one of the of the plurality of tungsten carbide cutters. Additionally, this embodiment might further comprise the at least one of the plurality of first cutters is positioned more proximally from a central longitudinal axis of the bit body than at least one of the of the plurality of tungsten carbide cutters. Some embodiments of the drill bit might include at least one of the plurality of blades supports a plurality of chisel cutters, wherein each chisel cutter has a top surface with two joining edges that extend to define an acute angle.

Additionally provided herein is a drill bit to advance a borehole comprising a bit body having a face on which is defined a plurality of blades extending from the face and separated by channels between the blades, each said blade supporting a plurality of first cutters; and at least two of the plurality of blades supporting at least one of chisel cutter, wherein the at least one chisel cutter has a top surface with two joining edges that extend to define an acute angle.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

The detailed description of some embodiments of the invention is made below with reference to the accompanying figures, wherein like numerals represent corresponding parts of the figures.

FIG. 1 is a photographic image of a chisel-shaped cutter;

FIG. 2 is a photographic image of a first drill bit incorporating at least one chisel cutter of FIG. 1 on at least one of the bit's cutting blades;

FIG. 3 is a photographic image of a second drill bit incorporating at least one chisel cutter of FIG. 1 on at least two of the bit's cutting blades;

FIG. 4 is a photographic image of a donut-shaped cutter;

FIG. 5 is a photographic image of a third drill bit incorporating at least one chisel cutter of FIG. 1 and at least one donut cutter of FIG. 4 on the same cutting blade;

FIG. 6 is a close-up photographic image of a portion of the drill bit of FIG. 5; and

FIG. 7 is a diagram of the drill bit of FIG. 5 being utilized against a rock wall.

DETAILED DESCRIPTION OF DRAWINGS

In the following detailed description of the invention, numerous details, examples, and embodiments of the invention are described. However, it will be clear and apparent to one skilled in the art that the invention is not limited to the embodiments set forth and that the invention can be adapted for any of several applications.

It is to be understood that this invention is not limited to particular aspects of the present invention described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as the recited order of events.

Where a range of values is provided herein, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits ranges excluding either or both of those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the methods and materials are now described.

It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

Referring now generally to the Figures and particularly to FIG. 1, FIG. 1 is a photo of a chisel cutter 100 having a chisel top 102, a chisel point 104, and a chisel base 106.

Referring now generally to the Figures and particularly to FIG. 2, FIG. 2 is a photo of a first drill bit 200 incorporating at least one chisel cutter 100 on at least one blade 202.

Referring now generally to the Figures and particularly to FIG. 3, FIG. 3 is a photo of a second drill bit 300 incorporating at least one chisel cutter 100 on at least two blades 202.

Referring now generally to the Figures and particularly to FIG. 4, FIG. 4 is a photo of a donut cutter 400.

Referring now generally to the Figures and particularly to FIG. 5, FIG. 5 is a photo of a third drill bit 500 incorporating at least one chisel cutter 100 and one donut cutter 400 on the same blade 202.

Referring now generally to the Figures and particularly to FIG. 6, FIG. 6 is a photo showing part of the drill bit 500 incorporating at least one chisel cutter 100 and one donut cutter 400 on the same blade 202.

Referring now generally to the Figures and particularly to FIG. 7, FIG. 7 is a diagram of the chisel cutter(s) 100 and donut cutter(s) 400 of the drill bit 500 being applied against a rock surface, such that the sharper chisel cutters 100 are directly cutting the rock head-on and the donut cutters 400 are positioned to grind against the trailing rock face. A drill bit that ideally incorporates both, particularly one with the chisel cutters 100 in front an both is able to apply these different tools to different jobs and drill better for longer before having to be replaced.

While selected embodiments have been chosen to illustrate the invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment, it is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 

What is claimed is:
 1. A drill bit to advance a borehole comprising: a a. bit body having a face on which is defined a plurality of blades extending from the face and separated by channels between the blades, each said blade supporting a plurality of first cutters: and b. at least one of the plurality of blades supporting at least one chisel cutter, wherein the at least one chisel cutter has a top surface with two joining edges that extend to define an acute angle.
 2. The drill bit of claim 1, wherein at least one of the plurality of first cutters comprises polycrystalline diamond compact (“PDC”).
 3. The drill bit of claim 1, wherein at least one of the plurality of first cutters defines a depression extending from the top surface and towards a central longitudinal axis of the bit body.
 4. The drill bit of claim 3, wherein the at least one of the plurality of first cutters comprises polycrystalline diamond compact (“PDC”).
 5. The drill bit of claim 1, wherein at least one of the plurality of first cutters comprises hot isostatic segments.
 6. The drill bit of claim 1, wherein at least one of the plurality of first cutters comprises hot diamond elements coated with a metal binder.
 7. The drill bit of claim 1, wherein at least one of the plurality of first cutters comprises diamond elements sintered within a tungsten carbide matrix.
 8. The drill bit of claim 7, wherein the at least one of the plurality of first cutters comprises hot diamond elements coated with a metal binder.
 9. The drill bit of claim 1, wherein the at least one of the chisel cutters comprises hot isostatic segments.
 10. The drill bit of claim 1, wherein the at least one of the chisel cutters comprises hot diamond elements coated with a metal binder.
 11. The drill bit of claim 1, wherein the at least one of the chisel cutters comprises diamond elements sintered within a tungsten carbide matrix.
 12. The drill bit of claim 7, wherein the at least one of the chisel cutters comprises hot diamond elements coated with a metal binder.
 13. The drill bit of claim 1, wherein the at least one chisel cutter is positioned more distally from a central longitudinal axis of the bit body than at least one of the plurality of first cutters.
 14. The drill bit of claim 13, wherein the at least one chisel cutter is positioned more distally from the central longitudinal axis of the bit body than all of the plurality of first cutters.
 15. The drill bit of claim 1, further comprising a at least one tungsten carbide cutter supported by the at least one blade of the plurality of blades.
 16. The drill bit of claim 15, further comprising a plurality of tungsten carbide cutters supported by the at least one blade of the plurality of blades.
 17. The drill bit of claim 16, wherein the at least one chisel cutter is positioned more distally from a central longitudinal axis of the bit body than at least one of the of the plurality of tungsten carbide cutters.
 18. The drill bit of claim 16, wherein the at least one of the plurality of first cutters is positioned more proximally from a central longitudinal axis of the bit body than at least one of the of the plurality of tungsten carbide cutters.
 19. The drill bit of claim 1, wherein at least one of the plurality of blades supports a plurality of chisel cutters, wherein each chisel cutter has a top surface with two joining edges that extend to define an acute angle.
 20. A drill bit to advance a borehole comprising: a a. bit body having a face on which is defined a plurality of blades extending from the face and separated by channels between the blades, each said blade supporting a plurality of first cutters: and b. At least two of the plurality of blades supporting at least one of chisel cutter, wherein the at least one chisel cutter has a top surface with two joining edges that extend to define an acute angle. 